turnip: call packing functions directly for pack_gmem_clear_value

This involves rolling our own int packing functions, because the u_format
versions do clamping which differs from VK spec requirement.

This reduces the size of libvulkan_freedreno.so significantly.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6304>
2 files changed